package com.acertificate.image;

import java.awt.Container;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class Image2Thumbnail {

	public static void main(String[] args) throws FileNotFoundException, IOException, InterruptedException {

		createThumbnail("f:/input.jpg", 200, 300, 100, "f:/out.jpg");
	}

	static void createThumbnail(String filename, int thumbWidth, int thumbHeight, int quality, String outFilename)
			throws InterruptedException, FileNotFoundException, IOException {
		Image image = Toolkit.getDefaultToolkit().getImage(filename);
		MediaTracker mediaTracker = new MediaTracker(new Container());
		mediaTracker.addImage(image, 0);
		mediaTracker.waitForID(0);
		double thumbRatio = (double) thumbWidth / (double) thumbHeight;
		int imageWidth = image.getWidth(null);
		int imageHeight = image.getHeight(null);
		double imageRatio = (double) imageWidth / (double) imageHeight;
		if (thumbRatio < imageRatio) {
			thumbHeight = (int) (thumbWidth / imageRatio);
		} else {
			thumbWidth = (int) (thumbHeight * imageRatio);
		}

		BufferedImage thumbImage = new BufferedImage(thumbWidth, thumbHeight, BufferedImage.TYPE_INT_RGB);
		Graphics2D graphics2D = thumbImage.createGraphics();
		graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
		graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);

		BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outFilename));
		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(thumbImage);
		quality = Math.max(0, Math.min(quality, 100));
		param.setQuality((float) quality / 100.0f, false);
		encoder.setJPEGEncodeParam(param);
		encoder.encode(thumbImage);
		out.close();
	}

}
